Apparatus for raising natural oils and other liquids by gaseous pressure



Jan. 4, 1949. N BRQWN 2,458,053

APPARATUS FOR RAISING NATURAL oILs AND OTHER LIQUIDs BY GAsRoUs PRESSURE 5 Sheets-Sheet 1 Filed Sept. 13. 1945 NoRMmv E' BRowN Jan. 4, 1949. N. F. BROWN APPARATUS FOR RAISING NATURAL OILS AND OTHER LIQU'IDS BY GASEOUS PRESSURE 5 Sheets-Sheet 2 Filed Sept.4 15, 1945 y a a. w w ww d .N m 111| 11111 M ff |l|1 I .N v A1, H 11 Iv 11 S f bw /mm 1|1H111| 1.1 V111 WIIL 1 11.- muvm A mw |11 A ,n m. .wk R Ram, mm wm .Sn n@ i. L. .MUG

mm vv G NATURAL OILS AND OTHER LIQUIDS BY GASEOUS PRESSURE 5 Sheets-Sheet 4 Filed Sept. 15. 1945 Illfllllllllllllll .114.; al. Irllllvllal. lllfllllnll' lililllll..nvlllllalllla I'Inlll la lullalnllnaln l lllll. Alli. lalll /y f IY .Illallllll [.ln 1 1 A n a 4 n l s A a l l l 1 l Jan. 4, 1949.

Filed Sept. 15, 1945 N. F. BROWN APPARATUS FOR RAISING NATURAL OILS AND OTHER LIQUIDS BY GASEOUS PRESSURE 5 Sheets-Sheet 5 f6 lu o 8f a I ,o 3

. IH as Patented Jan. 4, 1949 APPARATUS FOB RAIBING NATURAL OILS AND OTHER LIQUIDS BY GASEOUS PRES- SUBE Norman Fraser Brown, Stow, Scotland. assignor of one-half to Indo-Burma Petroleum Company Limited, Calcutta, India, a British-Indian company Application September 13, 1945, Serial No. 618,111

In Great Britain October 26, 1944 4 Claims. (Ci. 103-230 The present invention relates to apparatus for raising natural oils and other liquid by gaseous pressure by a displacement pumping system ot the kind comprising a displacement chamber adapted to be located below liquid level in the well and an eduction pipe vertically reciprocating in said chamber and adapted to be moved into one position to isolate the chamber from the well and connect it with the eduction pipe to permitl liquid collected in said chamber to be forced by gaseous pressure up the eductlon pipe, the pipe being adapted to be moved into another position to shut oft the supply of gaseous pressure, connect the interior of the chamber with the well to permit liquid to ilow into the chamber and isolate the chamber from the eduction pipe.

In the known apparatus for raising oil by the displacement pumping system, as the oil enters a port at th`e lower end of the displacement chamber under the influence of gravity, it forces out any gas remaining in the chamber, the gas escaping through a port at the upper end of the chamber directly into the well casing. With this arrangement diiiiculties are experienced in pumping oil which contains volatile constituents as gas tends to separate from the liquid as soon as it enters the chamber. In these circumstances before the displacement chamber is illled completely, or to the desired level, a point is. reached when the hydrostatic head of the column of separated oil partly lling the displacement chamber equals the hydrostatic head of the column of gassy oil outside,'and consequently the entry of further oil into the chamber ceases before the chamber is lled. l

It is an object of the present invention to provide means for preventing the aforesaid conditions and thereby ensure that the displacement chamber can be completely lled with oil irrespective of the degree of gassiness of the oil column in the well outside the chamber.

The present invention comprises apparatus for raising liquid in wells Iby the displacement pumping system, wherein liquid is collected in a displacement chamber from the well and subsequently raised up an eduction pipe by gas under pressure, an auxiliary chamber being provided with an exhaust port or portsior discharging the gas exhausted from the displacement chamber into the well casing at a distance above the chaml than the hydrostatic headoi settled or non-sassy ber which is such that the hydrostatic head of a L oil which would fill the displacement chamber.

With this arrangement the gassy oil will ow into the displacement chamber until there is suilicient settled oil to iill the displacement chamber completely at each cycle of operation of the apparatus.

To enable this invention to be fully understood it will now be described with reference to the accompanying drawings, in which:

Figs. l and 2 are diagrammatic views illustrating the invention,

Fig. 3 is a schematic diagram illustrating the lay out of liquid raising apparatus embodying the invention,

Figs. 4 and 5 illustrate the working oi the apparatus, and

Fig. 6 is a sectional elevation of the valve unit.

The operation of the pump is shown in Figs. 3 to 6 of the accompanying drawings wherein I is an oil well casing which is perforated to admit oil from the surrounding strata. The upper end of the casing is closed by a casing head 2 which supports a pipe 3 which extends through an aperture in the head 2 into the casing I. A pipe l is provided adi acent the upper end oif the casing for carrying off gas in the casing to a low pressure gas receiver 5.

The lower end of pipe 3 and the upper end of a pipe 'l are connected by a collar 6 and the lower end of pipe l is provided with a collar 8 to which is connected a cylinder 9 and sleeve I0. The lower end of the sleeve I0 is connected with a collar II to which cylinders I2, I3 are attached. The upper end of the casing I4a of the displacement chamber I4 is connected to the collar II and a sleeve 8'8, extending upwardly of the well rests on the packing ring 20 located on a shoulder on the outer face of the collar II. 68 engages the packing ring by gravity alone providing a simple seal against low differential pressures.

The collar 6 has a bore nearlyequal to that of the cylinders 9, I2 and I3 and provides an inner shoulder forming a seat -for the guide member 49 and forms a location point from which the positions of the parts connected with` the pipe 3 can be related to the positions of the parts 46, 41, 48 constituting the reciprocating oil pipe.

The collar 8 has an internal recess i5 andapertures f8 connecting the interior of the cylinders 9. I2 with the annular space Il.

The collar Il has vertical passages I8 connecting the space I'l with the chamber Il, and horizontal passages I9 connecting the interior of the The sleeve accepts cylinders I2, I3 with the interior oi the sleeve 58 without opening into the passages, I8.

The lower end. o! the casing I4a is connected by a collar 2| with a cylinder 22 whose lower end is attached to a collar 23 which supports a casing 24.closed at its lower end by a plug 25. The chamber enclosed by the casing 24 forms a continuation of the chamber I4 and the combined dimensions of the two parts o! this chamber, i. e., those enclosed by casings |4a and 24, are designed to allow the chamber to contain such a quantity nected by a ilexible pipe 58 with an oil/gas o1' liquid, that when displaced into the oil eduction pipe, it will form. therein a column of liquid of such length that the normal working gas pressure can force the column up the oil eduction pipe at the desired velocity.

A cylinder 30 extends between the collars 2| and 23, and the collar 2| is formed with slots 8| providing a passage between the interior of the casing I4a and the annular space 32.

The collar 23 is formed with vertical passages 33 connecting the annular space 32 with the interior of the -casing 24 and horizontal passages 34 connecting the interiors oi the cylinders 26 and 30 and ari-annular space between the cylinder 22 and a perforated screen 35 which extends between the collars 2| and 28.

A cylinder 26 depends from the collar 23 and its lower end is attached to collar 21 which supports an inner cylinder 28 and an outer sleeve 28 which terminates short of the plug 25. The collar 21 has a recess 36 and passages 31 connecting the interior of cylinders 26 and 28 with the annular space 38.

The cylinders 8, I2, I3, 26, 28 and 38 are all of substantially the same internal bore. The

separator 53.

A pipe 80 communicates with the cylinder 38 to deliver high pressure gas from a high pressure gas receiver 6I. The piston 42 is actuated to raise the oil pipe 46 by uid supplied under pressure from a container 82 connected to the lower end of the hydraulic cylinder 48.' The iluid is forced from the container 62 by high pressure gas led by a branch pipe 83 from the pipe 68,

cylinders 9, I2, and I3 are concentrically arranged and comprise one group and the cylinders 26, 28, and 38 are concentrically arranged and form a second group.

The cylinders in the first mentioned group are nearly concentric with those of the second group. All the cylinders are machined internally to provide a high polish and are formed with ared or bell-mouthed upper and lower ends.

The upper end of the pipe 3 supports a cylinder 39 the upper face of which forms the base of a hydraulic cylinder 48 closed by a cap 4|. A piston 42 is reclprocally mounted in the cylinder 48 and has integral hollow extension rods 43, 44 which extend through suitable packings in the upper and lower Walls of the cylinder 40, the upper end of the rod 43 being adapted to engage a collar 45 on the oil'eduction pipe 48 which extends through the rods 43, 44 and the piston 42 and interiorly of the pipe3 down into the well.

The lower end of oil pipe 46 is connected by a pipe 41 with the upper end of an oil pipe 48 the pipe 41 being tapered to provide against any sudden change of velocity of the oil where the pipe has a larger internal diameter than the pipe 48.

The lower end of the pipe 41 and the upper end of the pipe 48 are connected by a slotted guide member 48 the outer diameter of which is an easy sliding t in the pipe 3 and serves to guide and centralize the pipe 41 within the pipe the supply of gas being controlled by a valve 84 operated electrically by a timing device indicated by 65. The valve is of known two way type, adapted in one position to connect the interior oi' the container 62 with the pipe 63, and in the other position to connect the interior of the container to the exhaust connection 66. The container 62 is provided with a close-tting piston 61 which serves to isolate the pressure iluid which may be oil, from surface contact with 'air or gas above the piston. When the container 62 is connected to exhaust the oil pipe 46 descends by gravity moving the piston 42 downwardly with it. v

When the oil pipe 48 is in its lowermost position the piston 42 is at the lower end of cylinder 48, the slotted guide 48 is resting on the collar 6; the plunger 5I closes the upper end of cylinder 8; the plunger 52 closes the lower end of cylinder I2; the plunger 53 is below the end of cylinder I3; the plunger 54 closes the lower end of cylinder 38; and the plungers 55 and 56 are closing respectively the upper and lower ends of cylinder 28 isolating the perforations 51 of pipe 48.

With the apparatus in this position, oil from the casing I ows through the screen 35, passages 3,4, cylinder 26, recess 36 and passages 31, annular space 38 to illl the continuation or lower portion of the chamber I4. From thence the oil ows upwards within the casing 24 through passages 33, annular space 32, slots 3| and lls up the main portion of the chamber I4 formed by the casing I4a whilst gas that may be in .the

chamber is expelled through cylinder I3, passages I8, sleeve 68, and nally escapes to the casing I by holes 68a at the top of sleeve 68.

After a predetermined interval, the timing mechanism actuates the pilot valve 64 and the piston 42 raises pipe 46 to the position shown in Fig. 3. In this position, plunger 55 is positioned in cylinder 26 whilst plungers 56 and 54 are` raised higher up in cylinders 28 and 30 respectively. Plunger 5I is positioned in pipe 1 above the en d of cylinder 8,-plunger 53 is positioned in cylinder I3 closing its lower end whilst plunger 52 is raised in cylinder I2. Oil inlet passages 34 are then isolated between plungers 54 and 56 and the perforations 51 are in communication with the- .lowest portion of chamber I4 3. The guideis formed with vertical slots 58 to permit the lfree passage of gas.

The oil pipe 48 carries plungers 5|, 52, 53, 54,

end of the pipe 48 is closed and between thev plungers 55 and 56 it is formed with a series of i perforations 51. The various plungers form a as formed by cas'ing 24 via recess 36, passages 31 and annular space 38. Gas exhaust passages I8 are then isolated, between plungers 52 and 53.

Pressure gas is then permitted to flow from the4 gas container 6| via pipe 68, cylinder 38, pipe 3,

cylinder 8, recess I5, Vpassages I6, annular space I1,- passages I8, tothe top of the chamber I4. Oil is then displaced by the gas pressure via slots 5 9|, space 92, passages 39, down the outside and up the insidel ofs1eevei29, passages-I1 and periterations 61 into the oil pipe 46, and thence through pipe 41 into pipe 46.

After the slug has travelled a suitable distance up the pipe 46, thevalve 64 is actuated to exhaust the container 62 andthe pipe 46 descends by gravity to the lowermost position cutting oi! further supply of gas pressure to the chamber i4. The expansion of -the gas in` the ypipe 46 com- -pletes the delivery of the oil slug to the separator. The gas remaining in the chamber i4 is exhausted to the well casing via the exhaust sheath 69 and the chamber I4 rells with oil.

The particular point in the upward travel of the slug at which the pipe 46 is adapted to eut of! the supply of pressure gas may be varied according to the slug velocity and the depth oi.' the well.

The cutoff will normally be eiected to provide the use of gas in the pipe 46 expansionally when the top of the slug has reached the surface.

.'But in some cases the cut off may take place before, or after the top of the slug reaches the surface.

The cut off may be initiated by the cessation of electric current from the timing mechanism 66 tothe electro-magnetic pilot valve 64 in which case the duration of pressure gas input is predetermined to suit well conditions.

The slug of oil flows from the pipe 46 through pipe 68 into the oil/gas separator 59 followed by the gas under pressure which is behind the slug.

The separator 59 has a iioat 69 provided with an arm 10 adapted to operate a projection 1i oi' a valve 12 which is connected by a branch pipe 13 with the pipe 60 and by a pipe 14 with a valve unit 15. As more particularly shown in Fig. 6,` the valve unit comprises a main casing having an oil inlet 16 connected by pipe 11 with the lower end of the separator 59 and an oil outlet 19 having a spring-loaded valve 19 preierably embodying a dash-pot damping arrangement. The outlet 18 is connected by the pipe 19a; which includes an oil meter 80, with the oil receiver 8| from which it is delivered by the pipe 82 to a storage tank 83. The valve unit also includes a gas inlet 84, connected by a pipe 85 with the upper end of the separator 59, and a gas outlet 86 having a spring loaded valve 61, preferably embodying damping means. The outlet 86 is connected by the pipe 88 with a receiver 89 for gas at intermediate pressure. A further gas outlet 90 is provided which is connected by pipe 9| with the pipe 4 leading to the low pressure gas receiver 5.

The body of the valve unit has a valve seat 92 for engagement by a Valve 93 provided with a spring 94 tending to open the valve. A screw plug 95 is provided for adjusting the pressure of the spring 94 to determine the pressure at which the valve opens.

A spindle 96 extends through the valve body and is provided with valves 91, 98 for co-operation with valve seats 99. for controlling the ow of oil from the inlet 16 to the outlet 18. The spindle 96 also carries valves |0|, |02 for co-operation with valve seats |03, |04 for controlling the now of gas from the inlet 84 to the outlet 86. At the upper end the valve spindle is operated by a diaphragm having a charnber |06 on the upper face, which is connected with the pipe 14.

The spindle 96 is provided with a spring |01 ananas tending to raise the spindle and its lower end is formed with an extension |66 adapted to abut the valve 99 and maintain it closed when the spindle is in its lower position. ,4

As the oil flows up thepipe 46 and into the separator 69, the valve spindle is in the position shown in Fig. 6, the oil valve 91. 96 being closed and the gas valves 99, lll and |62 open so that .the low pressure gas contained in the tubing. 46 above the oil slug may be displaced at low pressure via the separator 69, pipe 66, valve 99, pipes 9| and '4 to the low pressure gas reservoir 6. The oil is adapted to enter the separator 69 tangentially to impart a spiral motion to the oil to assist separation of any gas therein. the gas under pressure which lifts the oil up the oil pipe, following the oil into the separator. As the level of oil rises in the separator, the float 69 is raised until the arm 10 depresses the projection 1| and actuates the valve 12 to permit pressure gas to flow to the chamber |66 via pipes 19 and 14 and move the spindle 96 to its lowermost position. opening the oil valves 91, 96 and closing the gas valves 93. |0| and |02. As soon as the necessary pressure has been built up in the separator 69 by the gas flowing into it, the oil is expelled through the pipe 11 and flows past the valves 91, 98, lifts the spring loaded valve 19 and iiows through the pipe 19a 'and via the collector 6| and pipe 82 to the storage tank Il. When the oil in the separator has reached a. predetermined low level, the arm 10 is lifted by the float 69 and the valve 12 returns by spring means to shut off the supply of gas from the pipe 13 and to connect the pipe 14 to atmosphere to exhaust the chamber |06.

The valve spindle 96 is now raised by its spring |01 to close the oil valves 91, 96 and open the gas valves l0| and |02, the valve 99 being free to open under spring action. The valve 61 is loaded .by its spring to open at a predetermined pressure, for example 50 lbs. per square inch and the spring 94 is adapted to open the valve 96 below the predetermined pressure, which in the example given r would be below 50 lbs. per square inch.

The gas in the separator ows through the pipe 65 to the inlet '84 and as it will normally be at a pressure in excess of that ,required to open the valve 81 this valve is raised by the gas which, however, maintains the valve 93 closed. The gas is delivered via pipe 66 to a receiver 99 for collecting gas at an intermediate pressure, which in the example is 50 lbs. per square inch. The gas is delivered from the receiver 69 via pipes |09, i I0 to a gasolene extraction plant and pipe ||2 to the second stage intake B of a two stage compressor unit I|3 which raises the pressure of the gas to the high pressure needed for operating the displacement pump and delivers it through' pipe ||4 to the high pressure receiver 6| .I

When the pressure of the gas flowing through the valve unit drops below the predetermined pressure of 50 lbs. per square inch, the valve 99 is opened by the spring 94 and valve 61 closes automatically. The remaining gas now flows past the valve 93 and through the pipes 9| .and 4 to the low pressure gas receiver 5 and is delivered from there via pipe I l5 to the ilrst stage intake A of the two-stage compressor unit H3 wherein itis raised to the intermediate pressure and then delivered via pipe ||0 plant III and pipe ||2 to the second stage intake of the two-stage compressor H6.

On the next operation of the displacement pump a fresh slug of oil is delivered to the separator 59 and when the oil level therein rises sufciently, the valve is iactuated and the spindle moved to its lower position and the cycle of operations described above is repeated.

Any surplus of low pressure gas, after making good any small losses in the closed system, is led through pipe I |21; for use as fuel. f

A reference to the diagrammatic views shown in Figs. 1 and 2 will enable the invention to be easily understood. As shown, Fig. 1 is a digrammatic view of the prior arrangement of a displacement pumping -chamber wherein a comprises the well casing, b the displacement chamber in which liquid is collected from the well through the aperture c. The eduction pipe is diagrammatically indicated at g and it will be understood that in actual practice this pipe is vertically reciprocated in the displacement chamber b and is provided with valve means which control the yadmission of the liquid through the ports c into the chamber b and the supply of fluid pressure tothe chamber to displace the liquid from the chamber up the eduction pipe in accordance with the steps in the cycle of the displacement pump. For .efiicient operation it is necessary that the chamber b should be completely filled with liquid during each cycle of the pumping system. However, in pumping oil or liquid containing volatile constituents gas tends to separate from the liquid as soon as it enters the chamber b. In prior constructions this separated gas was adapted to be exhausted directly into the well through the ports d at the upper end of the chamber b as shown in Fig. 1. It was found that this arrangement did not ensure that the chamber b was completely filled with liquid. due to the fact that when the hydrostatic head of the column a: of settled or non-gassy liquid in the chamber b in Fig. 1, equalled the hydrostatic head of the column y of gassy liquid in the well casing, extending vertically from the inlet port c to the gas exhaust ports d the entry of further liquid into the chamber b ceased. Accordingly the volume of liquid collected in the chamber varied according to the percentage of volatile liquids in the liquid and the desired lling of the chamber to a constant level at everyl cycle of the pumping system could not be attained.

As shown diagrammatically in Fig. 2 this drawback is overcome by providing an auxiliary chamber e forming an upper extension of the displacement chamber b. The chamber e is formed with annularly arranged ports f exhausting gas into the well casing at a point spaced above the upper end of the chamber b. As liquid enters the chamber b it expels any separated gas into the chamber e through the annularly arranged ports d. The chamber e is of such dimensions that the chamber b is completely filled with liquid before the point is reached wherein the hydrostatic head of the column of settled or nongassy liquid a," in the displacement chamber equals the hydrostatic head of the column of gassy liquid y in the well casing extending from the inlet port c in the chamber b to the gas exhaust ports f. f

It will be understood that although the invention is particularly applicable to the apparatus lan eduction pipe vertically reciprocable in said displacement chamber; a-'plurality-of valve means actuable by said eduction pipe upon reciprocation thereof to one position for admitting liquid to the displacement chamber from a space around the` displacement chamber, uncovering the gas inlet ports connecting the upper part of the displacement chamber with the 'auxiliary chamber, and closing the eduction pipe` from the displacement chamber; and actuable, upon reciprocation of the eduction pipe to another position thereof, for

\ closing said displacement chamber from said space, covering said gas inlet ports, admitting gaseous uid to the upper part of said displace- 'ing from the oil entry in the lower end of the displacement chamber to the height of the exhaust 'port or ports in the auxiliary chamber, is greater than the hydrostatic head of settled or nongassy oil which would illl the displacement chamber.

2. Apparatus for raising liquids in Wells by gaseous pressure comprising' a displacement chamber adapted to be disposed be'ow liquid level in a well; an auxiliary chamber extending from the upper end of/ said displacement chamber; a series of annularly arranged gas inlet ports in the lower end of said auxiliary chamber opening into the upper end of said displacement chamber; a series of annularly arranged gas outlet ports in said auxiliary chamber spaced upwardly of the upper end of the dispacement chamber and opening into the Well; a gas pipe opening to said displacement chamber; a source of gaseous pressure; means connecting said source to said gas pipe; and eduction pipe vertically reciprocable in said displacement chamber; a plurality of valve means actuable by said eduction pipe upon reciprocation thereof to one position for admitting liquid to the displacement chamber from a space around the displacement chamber, uncovering the gas inlet ports connecting the upper part of the displacement chamber with the auxiliary chamber, and closing the eduction pipe from the displacement chamber; and actuable upon reciprocation of the eduction pipe to another position thereof, for closing said displacement chamber from said space, covering said gas inlet ports,

admitting gaseous uid to the upper part of said l displacement chamber, and opening the eduction pipe to the lower part of the displacement chamber; said gas outlet ports in the auxiliary cham-- settled or nongassy foil which would iill the displacement chamber. l REFERENCES CITED .c

3, Apparatus wording m claim 1 wherein The following references 'are o! record in the the-said auxiliary chamber comprises a cylindrical 111 0f this Patenti member of substantially the same diameter as the '5 UNITED STATES PATENTS displacement chamber.

NORMAN FRASER BROWN. 

